Drum internals



April 29, 1958 w. R. TAGG E RT ,8

DRUM INTERNALS Filed July 22, 1954 2 Sheets-Sheet l INVENTOR MLMER fi. Roar/Pr WWW MW A TORNEY April 29, 1958 w. R. TAGGERT DRUM INTERNALS 2 Sheets-Sheet 2 Filed July 22. 1954 United States Patent DRUM INTERNALS Wilmer R. Tagger-t, Worcester, Mass, assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Application July 22, 1954, Serial No. 444,960

2 Claims. (a. 122-459) This invention relates to drum internals, and more particularly to apparatus for use with condenser-type steam purifiers.

In the generation of steam it is usual practice to provide means for purifying the steam before passing it into the superheater. For that purpose, certain steam treating apparatus has been placed in the path of the steam as it passes through the steam and water drum. One of the principal pieces of apparatus for this purpose is the condenser, an effective type of which is shown in the patent to Andrews, 2,424,212, issued July 22, 1947. It has been proposed that this condenser be segregated at one side of the drum so that boiler water will be excluded therefrom and so that variation in water level during changes in load will not produce a change in the effective area of the condenser due to the immersion of the condenser in varying levels of water. However, one difficulty encountered in such a segregation technique is that the condensate from the condensers and also from other apparatus, such as dryer cartons, collects in the trough and may accumulate sufficiently to cover the condensers and thus inhibit their action. The present invention obviates this difliculty in a novel and practical manner.

It is therefore an outstanding object of the present invention to provide an eflfective means for draining condensate from a trough underlying condensers in a steam boiler.

It is a further object of the invention to provide an apparatus for draining the condensate trough of a steam and water drum which apparatus makes use of the force of flow of the feed water entering the boiler.

A still further object of the invention is the provision of a drainage apparatus for drum internals which is rugged and simple in construction and which will not be rendered ineflective by chemical deposits, extreme temperatures, and the like.

Another object of this invention is to provide an apparatus for reducing carryover in the steam purification apparatus of a steam generating unit.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to certain of its structural fea tures, as illustrated by the accompanying drawings in which:

Figure 1 is a vertical sectional view of a steam-andwater drum and its internals, for use with a steam generating unit, embodying the principles of the present invention.

Figure 2 is a perspective view of certain of the elements shown in Figure l.

Figure 3 is a view of the apparatus of the invention taken on the line 3-3 of Figure 1, and

Figure 4 is a sectional view taken on the line 44 of Figure 1.

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Referring first to Figure 1, wherein is best shown the general features of the invention, the steam and water drum, generally designated by the reference numeral 10, is shown as comprising an elongated tubular member 11 closed at the ends by semi-spherical end members 12 having manholes 13 therein sealed by suitable closures 14. Extending longitudinally of the drum for most of its length is a trough 15. The trough defines an upwardly opening enclosure, the upper edge of which is well above the maximum level of the boiler water. Extending from the drums are downcomer tubes 17 of the usual type. The trough 15 is made up of a bottom member 16 and a vertical wall 18.

A longitudinal feed water header 21 lies in the lower portion of the trough 15. A series of condensers 22 extend upwardly from the header 21 in a generally vertical direction. A central tube 23 of each condenser bends downwardly and its end is situated under the minimum water level of the drum. A series of steam release tubes 24 is arranged around the drum, while the steam tubes 25 are connected to the drum in its upper portion and lead to the superheater now shown. A downwardly depending separating wall 25 extends from the wall of the drum adjacent the steam, tubes 25 and defines with the upper portion of the trough 15 a passage 27. A series of dryer cartons 28 is supported in the space between the wall of the drum and the separating wall 26. A drainage tube 29 extends from a lower corner of the dryer cartons 28 to the lower portion of the trough 15. A bottom member 1d of the trough 15 is made up of a fixed member 3t] which is fastened to the wall of the drum and an adjustable member 31 which extends outwardly toward the center of the drum and is bolted to the fixed member 3%. The lower portion of the vertical wall 13 of the trough 15 is provided with a plate-like flange 32 which is parallel to and slightly spaced from the inner portion of the member 33. of the bottom. A slot 33 is thus provided between the flange 33 and the member 31 and it is in this slot that the discharge end of each condenser 22 resides. This discharge end is flared out as is best shown in Figure 3, for a purpose to be explained more fully hereinafter. A series of baflle plates 34 are provide adjacent the steam release tubes 24.

Referring to Figures 2, 3, and 4, it can be seen that each of the central tubes 23 of the condensers 22 is provided at its discharge end with a flared nozzle 35. These nozzles reside in the space 33 between the flange 32 and the member 31. The spacing of the condensers and the amount of flare of the nozzles 35 is such that the flare spread of the nozzles 35 occupies approximately one-half of the lineal extent of the slot 33 and the extension lines of the sides intersect within the space 33. While in a vertical direction, the thickness of each nozzle 35 is in the order of one-third of the vertical space in the slot 33, as is best shown in Figure 4.

The operation of the apparatus will now be evident from the above description. Feed water enters the system through the header 21 and from the header the water flows upwardly through each condenser 22 absorbing heat from the extended surface thereof. The water then passes downwardly into the lower portion of the steam-and-water drum ifi through the nozzles 35 at the extremities of the condenser center tubes: 23. While passing through the heat absorbing surfaces of the boiler, the water is converted to steam and the steam enters the drum it) through the steam release tubes 24. The steam passes through the battles 34 and then passes upwardly, entering the passage 27 between the separating wall 26 and the upper portion of the vertical Wall 18 of the trough 15. It then passes over the condensers 22 where a portion is condensed and most of the impurities are removed; the condensate drops into the lower portion of the trough through the nozzles 35.

15. ..The. steam .then passes upwardly through the dryer cartons 28 on the other side of the separating wall 26, the cartons removing droplets contained in the flow.

:.Droplets:'collected:by the cartons drop downwardly into 1 thetrough alsot through the drain pipe-29. :It is necessary to remove'the condensate irom the trough 15 more rapidly 'than'would':bespossible by'natural flow-and also it is necessaryto: keep the level of water in the trough l5 considerably lower than the level in the remainder of the drum. This is accomplishedxby means of the aspiratory efiect of the-Water passing out of the toad :rs 222 The force of the feed water flowingthrough. the slot 33 is suflicient to drain the troughlE and to permit theme of the entire'vertical height of thercondenser 22. It canbe'seen from Figure 3 that the flare angles of the nozzles intersect within the slot33=, thus producing aspiration all along the trough.

It can'be seen, then,thatwith the use of the apparatus described above it. is possible to aspirate boiler water and condensate throughthe slot 33 by use of the energy available in the feed water flow through the condensers 22, thus effecting a lower boilerrwater level in the trough 15 than in the main compartment of the drum and thus providing a greater elfective area for steam passage through'the condensers 22. Also, it is possible to provide a lower liquid level in the chamber behind the wall 18 than in the drum proper, thus reducing the level of the foam blanket in the trough 15 with the resulting reduction of carryover. Furthermore, this arrangement prevents any surge or roll of water in the drum from getting behind the Wall 18 and causing carryover.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the'material spirit thereof. it is not, however, desired to confine the invention to the exact form herein shown and described, butit is desired to include all such as properly come within the scope claimed.

rounding-the said series, the said-trough consisting of a first portion underlying the series and a second portion extending generally vertically from a point adjacent to the first portion to a point well above the normal level of water in the drum, whereby said trough is open at the top to the steam spaceof the drum, parts of the first portion of the trough and the second portion of the trough being formed to extend substantially parallel with and closely adjacent to each other to form a narrow elongated passage which communicates between the space enclosed by the trough and the remainder of the steam-and water drum, discharge end of the condensers residing in the said passage and discharging the feed-waterparallel to the parts of the trough forming the passage, whereby liquid lying in the trough is aspirated into the main part of the drum.

2. A steam generating apparatus comprising a steamand-water drum, steam releasetubes-entering the said drum, steam outlet tubes leaving said drum, a series of steam purifying devices lying in the path of fiow of steam from the stearn release tubes to the steam outlet tubes, a trough underlying and partially surrounding the said series, the said trough consisting of a first portion underlying the series and the second portion extending generally vertically from a point adjacent to the first portion to a point well above the normal level of water in the drum, whereby said troughis open at the top to the steam .space of thedrurn, parts of the first'portion of the trough and the second portion of the trough being formedto extend substantially parallel with and closely adjacent to each other to form a narrow elongated passage which communicates between the space enclosed by the trough and the remainder of the steam-and-Water drum, means for introducing feed water into said drum comprising tubes having discharge ends disposed within said passage, the said means discharging feed water parallel to the partsof the trough forming the passage whereby liquid lying in the trough is aspirated into the main part of the drum;

References Cited in the file of this patent UNITED STATES EATENTS 2,287,592 Andrews June 23, 1942 2,300,852 Wood Nov. 3, 1942 2,424,212 Andrews et al. July 22, 1947 2,574,370 Bailey Nov. 6, 1951 

